The database used there is not collected with the normal piwik javascript, and could be the culprit. I have replicated this bug on another host/system, but have not tried replicating it with another database.

Oh, and I should add that this Amazon instance is very slow and would normally take some seconds to load data. You can see the same Piwik version with the same database working with Actions enabled on http://piwik.travelistics.org